1. Field of the Invention
The present invention relates to a slide surface construction and particularly, to a slide surface construction formed of an aggregate of metal crystals and having a high hardness.
2. Description of the Related Art
One example of the conventionally known slide surface constructions of this type is a Fe deposit layer which is formed on an outer peripheral surface of a pipe-like substrate made of a steel in a piston pin for an internal combustion engine for the purpose of enhancing the wear resistance.
However, the known slide surface construction suffers from a problem that under existing circumstances where speed and output of the internal combustion engine have tended to increase, the known slide surface construction is not sufficient in an oil retaining property, namely, oil retention and poor in seizure resistance due to a relatively smooth slide surface thereof.
Therefore, the present applicant has previously developed a slide surface construction including a large number of metal crystals in a slide surface thereof (for example, see Japanese Patent Application Laid-open No.174089/94).
If the slide surface construction is formed in this manner, adjacent pyramid-shaped metal crystals assume mutually biting states and hence, the slide surface takes on an intricate aspect comprising a large number of fine crests, a large number of fine valleys formed between the crests, and a large number of fine swamps formed due to the mutual biting of the crests. Therefore, the slide surface construction has a good oil retention. Thus, the seizure resistance of the slide surface construction is enhanced.
However, as a result of various reviews of the slide surface construction, it has been made clear that the slide surface construction has a relatively low hardness and hence, in order to accommodate a more severe sliding environment, it is necessary to enhance the hardness of the slide surface construction and to inhibit the wearing of the pyramid-shaped metal crystals in the sliding environment to maintain the good oil retention of the slide surface construction.